Take the data path from config

lib/index.js

@@ -35,6 +35,10 @@ function GitStats(config, data) {
         self.config = this.getConfig();
     }
 
+    if (self.config.data_path && !data) {
+        data = selc.config.data_path;
+    }
+
     this.path = Abs(Deffy(data, DEFAULT_STORE));
 
 }